package com.content.management.util;

import javax.servlet.http.HttpServletRequest;

/**
 * @author xinghu
 * @version 1.0
 * @date 2020/4/4 8:09 下午
 */
public class HttpHelp {

	private static final String UNKNOWN = "unknown";

	public static String getIPAddress(HttpServletRequest request) {
		String ip = null;

		// X-Forwarded-For：Squid 服务代理
		String ipAddresses = request.getHeader("X-Forwarded-For");

		if (ipAddresses == null || ipAddresses.isEmpty() || UNKNOWN.equalsIgnoreCase(ipAddresses)) {
			// Proxy-Client-IP：apache 服务代理
			ipAddresses = request.getHeader("Proxy-Client-IP");
		}

		if (ipAddresses == null || ipAddresses.isEmpty() || UNKNOWN.equalsIgnoreCase(ipAddresses)) {
			// WL-Proxy-Client-IP：weblogic 服务代理
			ipAddresses = request.getHeader("WL-Proxy-Client-IP");
		}

		if (ipAddresses == null || ipAddresses.isEmpty() || UNKNOWN.equalsIgnoreCase(ipAddresses)) {
			// HTTP_CLIENT_IP：有些代理服务器
			ipAddresses = request.getHeader("HTTP_CLIENT_IP");
		}

		if (ipAddresses == null || ipAddresses.isEmpty() || UNKNOWN.equalsIgnoreCase(ipAddresses)) {
			// X-Real-IP：nginx服务代理
			ipAddresses = request.getHeader("X-Real-IP");
		}

		// 有些网络通过多层代理，那么获取到的ip就会有多个，一般都是通过逗号（,）分割开来，并且第一个ip为客户端的真实IP
		if (ipAddresses != null && !ipAddresses.isEmpty()) {
			String[] ips = ipAddresses.split(",");
			if (ips.length > 0) {
				ip = ips[0];
			}
		}

		// 还是不能获取到，最后再通过request.getRemoteAddr();获取
		if (ip == null || ip.isEmpty() || UNKNOWN.equalsIgnoreCase(ipAddresses)) {
			ip = request.getRemoteAddr();
		}
		return ip;
	}
}
